Method and apparatus for checking guide-roll alignment in a continuous-casting machine

ABSTRACT

A method and apparatus for checking the vertical and rotational alignment of guide rolls of a continuous-casting machine with respect to one another and with respect to a mold thereabove. Apparatus includes a self-centering target which is suspended into the roll pass from a reeling mechanism mounted on the mold. The target is moved to various levels in the roll pass and sighted on with a transit mounted on a stand over the mold and centered with respect to the mold.

United States Patent [191' Bengel et al. 1 1 Feb. 4, 1975 I [54] METHODAND APPARATUS FOR 3,165,835 1/1965 Duncan 33/286 CHECKING GUIDDROLLALIGNMENT 1N 3,255,530 6/1966 Johnson 33/286 A CONTINUOUS-CASTINGMACHINE [75] Inventors: Thomas G. Bengel, Plum Borough; Primary Examine-Har y N. ian

Joseph S. Giunia, Monroeville Assistant ExaminerRichard R. StearnsBorough; Thomas E. Nicely, Attorney, Agent, or Firm'Walter P. WoodWestmoreland, all of Pa.

[73] Assignee: United States Steel Corporation,

Pittsburgh, Pa. [57] ABSTRACT [22] Filed: Sept 1972 A method andapparatus for checking the vertical and [21] A l N 289,922 rotationalalignment of guide rolls of a continuouscasting machine with respect toone another and with I respect to a mold thereabove. Apparatus includesa [52] U.S. Cl. t. 33/286, 33/228, selhcentering target which isSuspended i the l [51] Int. Cl G016 15/00 pass from a reeling mechanismmounted on the mold [58] Fleld of Search 33/228, 286, 293 The target ismoved to various levels in the To pass and sighted on with a transitmounted on a stand over [56] References C'ted the mold and centered withrespect to the mold.

UNITED STATES PATENTS v 2,198,837 4/1940 Morgan 33/286 4 Claims, 7Drawing Figures O 090 OOHOOoooooooo o PATENTEU 3.863.356

SHEET 20F 4 PATENTEUFEB M5 SHEEI 3 BF 4 PATEN-TEDFEB 4% I 3863,1356

sum nor 4 METHOD AND APPARATUS FOR CHECKING GUIDE-ROLL ALIGNMENT IN A-CONTINUOUS-CASTING MACHINE This invention relates to an improved methodand apparatus for checking guide-roll alignment in a continuous-castingmachine.

In a conventional continuous-casting operation, liquid metal is pouredthrough an open-ended watercooled vertically oscillating mold. Acasting, which at this stage has only a relatively thin solidified skinand a liquid core, emerges continuously from the lower end of the mold.Immediately beneath the mold the casting travels between guide rollswhere water is sprayed on its surface to effect further solidification.The guide rolls define a pass which confines the casting and which mustbe accurately aligned both vertically and rotationally throughout itsheight and accurately aligned with the mold. Any misalignmentof theguide can cause defects in the casting, or even rupture the skin andcause a break-out of liquid metal.

Although our invention is not limited to use with casting machines ofany specific construction, it is particularly useful as applied to guiderolls which are journaled in sectional racks of the construction shownin Hofmann and Stull US. Pat. No. 3,672,438 of common ownership. Thepatent shows vertically aligned rack sections, each of which includes arigid cage and idler rolls journaled within the cage to encompass foursides of a casting. Each rack section is supported ona respective pairof arms hinged to a supporting structure,

whereby the arms and section can swing out of the path of the casting toenable the section to be lifted from the arms and removed for servicing.When the rack sections are returned to their operative positions in thepath of the casting, they must of course be accurately realigned, andthis is accomplished by inserting shims between the cages and thesupporting structure.

Heretofore roll alignment has been checked either by suspending aplumb'bob from the mold through the rack sections and measuring thedistance from the plumb bob line to reference surfaces or'points on therack sections, or by sighting down the roll rack from a vertical transitmounted on a tripod over the mold. Neither procedure has been fullysatisfactory. Small movement of the supporting structure or plumb bobline interferes with accuracy. Use of a plumb bod is timeconsuming,especially since the interior of the rack sections is not easilyaccessible. When a vertical transit is used, it is necessary to insert atarget repeatedly at different levels in the rack, likewise atime-consuming and awkward procedure.

An object of our invention is to provide an improved method andapparatus for checking roll alignment and achieving greater accuracythan procedures'used heretofore, and also accomplishing the operationmore easily and expeditiously.

A more specific object is to provide a roll-alignment checking apparatuswhich includes a self-centering target movable vertically between guiderolls to all levels below a mold, and a reeling mechanism and a transitstand both to be mounted on the mold for suspending the target andsupporting a vertical transit.

A further object is to provide, as a subcombination of the foregoingapparatus, a self-centering target for installation between the guiderolls of a continuouscasting machine.

In the drawings:

FIG. 1 is a diagrammatic vertical sectional view of a mold and guiderolls on which our alignment-checking apparatus is installed;

FIG. 2 is a top plan view of a roll-rack section in which is installedthe self-centering target embodied in our apparatus, the viewbeing-taken on line llll of FIG. 1;

FIG. 3 is a vertical section on line IIl-lll of FIG. 2 with theroll-rack omitted;

FIG. 4 is a vertical section on line IV-IV of FIG. 2 again with the rollrack omitted;

FIG. 5 is a side elevational view of the reeling mechanism and transitstand embodied inour apparatus;

FIG. 6 is a horizontal section on line VIVI of FIG.

5; and

FIG. 7 is a horizontal section on line VII-VII of FIG. 5.

FIG. 1 shows diagrammatically a portion of a continuous-casting machinewhich includes a mold l0 and series of guide rolls 12 below the mold.The latter are journaled in a suitable frame or cage 13. Both the moldand guide rolls may be of conventional construction, or the guide rollsmay be arranged in rack sections 14, 14a and 14b constructed as shown inthe aforementioned patent. Hence no more detailed description of thecasting machine is deemed necessary.

Out alignment-checking apparatus comprises a selfcentering target 15installed within the pass defined by the guide rolls 12, a transit stand16 mounted on the mold l0, and a reeling mechanism 17 also mounted onthe mold. We suspend the target from the reeling mechanism with aflexible double line 18. The stand 16 carries a conventional verticaltransit l9.

FIGS. 2, 3 and 4 show'details of the self-centering target 15. Thetarget includes a pair of diagonally opposed vertically extending angleirons 22 and 22a which afford four roll-contacting faces 23 each lyingat a right angle to the adjacent such facefMounting bars 24 and 24a arewelded across the angle irons 22 and 22a respectively at the upper andlower ends of each angle iron. A diagonally extending grid support 25spans the space between the two upper mounting bars, and is fixed to theupper edge of bar 24 with cap screws 26, but slidably connected to theupper edge of bar 24a with similar capscrews which extend through slots27. The upper face of support 25 carries a grid pattern 28, the centerof which lies on the vertical center line of the roll pass when theroll-contacting faces 23 are in contact with rolls 12, that is, when thetarget is set to be sighted on, as hereinafter explained. The support 25preferably also carries a light stand 29 which contains -a batteryoperated light directed toward the grid pattern 28. v

We bolt a sheave housing 32 to the underside of the grid support 25 andjournal a pair of sheaves 33 and 33a within the housing at opposite endsthereof. The housing extends diagonally of the roll pass, but at rightangles to the grid support 25. The line 18 extends under support 25 andhousing 32 and around sheaves 33 and 33a, as shown in FIG. 4, forsupporting and raising the target. At its opposite ends the housingcarries upstanding guides 34 for the line 18. Removable pins 35 retainthe lines in the guides. The bottom edges of the mounting bars 24 and24a carry eye ,bolts 36 to which we connect a line 37 for pulling thetarget downwardly through the roll pass.

We bolt vertically extending plates 39 and 39a to the two mounting bars24 and to the two mounting bars 24a respectively. We fix upper and lowerbolts 40 to the plate 39 with nuts 41 which bear against opposite facesof the plate. Bolts 40 extend diagonally of the roll pass in the samedirection as the grid support 25. These bolts are slidably received inholes 42 in the plate 39a, and carry nuts 43 limiting relative outwardor expension movement of the plate and angle iron 22a. Bolts 40 carryadditional nuts 44 and compression springs 45 which bear at oppositeends against nuts 44 and plate 39a, thus urging the angle irons apart toexpand the target. An adjusting screw 46, which has right and left handthreaded sections extending in opposite directions from a handwheel 47fixed to its midportion, is

threadedly engaged with nuts 48 and 48a. These nuts are slidably butnon-rotatably mounted in brackets 49 and 49a carried by the plates 39and 39a respectively.

To insert the target 15 in the roll pass or remove it therefrom, we turnthe screws 46 in a direction to pull the two angle irons 22 and 22atoward each other against the action of springs 45 and thus contract thetarget. In this position of adjustment the target can move freelythrough the mold 10. When the target is within the rolls, we turn thescrew in the opposite direction a sufficient distance that the springs45 expand the target and force'the roll-contacting faces 23 of angleirons 22 and 22a into contact with rolls 12. In this position the gridpattern 28 is centered within the roll pass. It is of course necessarythat each target be dimensioned to fit a specific set of guide rolls. 1

FIGS. and 6 show details of the transit stand 16 and reeling mechanism17. The transit stand includes four legs 52, a top plate 53 fixed to theupper ends of the legs and a base plate 54 fixed to the lower endsL Thetop plate 53 carries a conventional transit adapter 55 on which we mountthe'aforementioned transit 19. The base plate 54 carries four dependingfixed blocks 56, two of which abut one inside of mold l0 and the othertwo of which abut a second inside face of the mold at right angles tothe first. The base plate 54 also carries four depending brackets 57 inwhich thumb screws 58 are threadedly engaged. Two of the thumb screwsabut one inside face of mold l0 opposite two blocks 56, and the othertwo thumb screws abut the fourth inside face of the mold. The centralportion of the base plate is open as indicated at 59.

The reeling mechanism 17 includes a mounting plate 62 which hasdepending brackets 63 and thumb screws 64 threadedly engaging thebrackets. The central portion of plate 62 is open as indicated at 65. Wemount the reeling mechanism on mold by tightening the thumb screws 64against two opposed outside faces of the mold. One edge of plate 62carries a pair ofupstanding legs 66 and 66a which carry a pair ofaligned bearings 67. A shaft 68 is journaled in bearings 67 and carriesa reel 69 and a hand crank 70. Relatively long and relatively shorthorizontal arms 71 and 71a are fixed to legs 66 and 66a. We journalsheaves 72 and 72a to arms 71 and 71a, which sheaves are tangentiallyaligned with sheaves 33 and 33a respectively of target 15. Line 18 isattached at one end to sheave 72a, extends around sheaves 33 and 33a onthe target 15, as already described, and around sheave 72, and is woundon reel 69. Thus turning the reel in the counterclockwise directionpulls the target upwardly through the roll pass. I

For the purpose of properly aligning the transit 19 with the roll pass,we temporarily mount a mold target 75 within the opening 59 in the baseplate 54 of the transit stand 16. The upper face of the mold targetcarries a grid pattern 76 similar to the grid pattern 28 on theself-centering target 15. The mold target has fixed blocks 77 andadjustable set screws 78 which engage the base plate 54-at the inneredge of its opening 59 to center the grid pattern 76 with respect tomold 10. With the grid pattern centered, we can center the transit 19with respect to the mold.

According to our method of checking alignment of the guide rolls 12, wecontract the self-centering target 15 and insert it through the mold 10into the roll pass.

We install the transit stand 16, transit l9, and reeling mechanism 17 onthe mold. We lower the self= centering target approximately to thebottom of the guide roll rack, and operate the adjusting screw 46 toexpand the angle irons into contact with the rolls. We center thetransit 19 by using the mold target 75 and remove the latter. We sightdown the mold and rack on the grid pattern 28, moving the targetsuccessively to various higher levels along the height of the rack. Aslong as the rolls are properly aligned, the grid pattern 28 remainscentered and angularly aligned with respect to the transit. Any verticalor angular misalignment is readily corrected, as by inserting orremoving shims in the example of a mold rack constructed as shown in theHofmann and Stull patent.

From the foregoing description it is seen that our invention affords asimple effective method and apparatus for checking the alignment ofguide rolls of a continuous-casting machine. Apparatus of similarconstruction readily can be dimensioned and proportioned for guide rollswhich define a pass of any rectangular cross section. The apparatus ishighly accurate and overcomes problems heretofore encountered.

We claim:

1. In an apparatus for checking alignment of guide rolls of a continuouscasting machine with respect to one another and with respect to a moldthereabove, said apparatus comprising:

a target adapted to be lowered through a mold into the roll pass;

a vertical transit;

a stand for positioning and centering said transit over the mold;

a reeling mechanism adapted to be mounted on the mold; and

a line suspending said target from said reeling mechanism for movingsaid target to various levels within the roll pass to be sighted on bysaidtransit;

the improvement in which said target includes:

a pair of diagonally opposed angle irons having rollcontacting faces atright angles to one another;

a diagonally extending support; a

means fixing said support with respect to one angle iron and permittingrelative sliding movement between said support and theother angle iron;

spring means urging said angle irons apart to expand said target;

means for contracting said target against the action' of said springmeans; and

a grid pattern on said support centered with respect to the roll passwhen the target is expanded into contact with the rolls.

2. An apparatus as defined in claim 1 comprising in addition a moldtarget for temporary installation on the mold to enable said transit tobe centered.

3. An apparatus as defined in claim 1 in which said target furthercomprises a sheave housing carried by 5 said line being wound saidsupport, and sheaves journaled to said housing,

6. said line extending around said sheaves.

'4. An apparatus as defined in claim 1 in which said reeling mechanismincludes a mounting plate, a reel, and means journaling said reel onsaid mounting plate,

on said reel.

ill 1 0 1 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION5,865,356 February A, 1975 Patent No. v Dated Thomas G; Bengel et a1.

Inventor(s) It is certified that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 18, after "guide" rolls should be insertedo Column 2,line 27, "Out" should be Our Column 5, line 8, "expension" should beexpansion .line 59, after "inside" face should be inserted.

Signed and sealed this 20th day of May 1.975.

(SEAL) Attest:

C MARSHALL DANN RUTH C. MASON Commissioner of Patents Attesting Officerand Trademarks -ORM PO-1050 (10-69) UsCOMM-DC B0376-P69 U45. GDVERNMENYPRINTING OFFICE 1 9. 93 o

1. In an apparatus for checking alignment of guide rolls of a continuouscasting machine with respect to one another and with respect to a moldthereabove, said apparatus comprising: a target adapted to be loweredthrough a mold into the roll pass; a vertical transit; a stand forpositioning and centering said transit over the mold; a reelingmechanism adapted to be mounted on the mold; and a line suspending saidtarget from said reeling mechanism for moving said target to variouslevels within the roll pass to be sighted on by said transit; theimprovement in which said target includes: a pair of diagonally opposedangle irons having roll-contacting faces at right angles to one another;a diagonally extending support; means fixing said support with respectto one angle iron and permitting relative sliding movement between saidsupport and the other angle iron; spring means urging said angle ironsapart to expand said target; means for contracting said target againstthe action of said spring means; and a grid pattern on said supportcentered with respect to the roll pass when the target is expanded intocontact with the rolls.
 2. An apparatus as defined in claim 1 comprisingin addition a mold target for temporary installation on the mold toenable said transit to be centered.
 3. An apparatus as defined in claim1 in which said target further comprises a sheave housing carried bysaid support, and sheaves journaled to said housing, said line extendingaround said sheaves.
 4. An apparatus as defined in claim 1 in which saidreeling mechanism includes a mounting plate, a reel, and meansjournaling said reel on said mounting plate, said line being wound onsaid reel.